Spring liner



April 21; 1942- l T. H. 'rHoMlfsoN 2,280,201

SPRING LINER F'iled April 7, 1941 lllll). lull un lill'l IH 3mm.. .220m J1'. T/zompog #31 26 22 f fw n Patented Apr.` 21, 1942 N i UNITED STATES "PATENT OFFICE srarNGruNnR `T'imr'rH. Thompson, Detroit- Application April 7,1941, serial Noesms u iloiaims, (291;267547);

, Heretofore, liners orinserts for laminated `leaf springs have been provi-dedcwith fastening or holding means such as pins, projections and the l like, arranged to extend` into complementary openings in an adjacent leaf spring` in order to maintain the liner in lrelatively fixed position With respect to one leaf spring upon relative movement of the other adjacent leaf `of the spring. In other words,A it isdesired to maintain the liner; in fixed positionwith respect to one adjacent leaf (hereinafter called the relatively stationary leaf) and to provide for relative movement between the liner `and ,the other adjacent leaf. Since in springsof this type the frictional engagement of the movable surface of the liner may become greater than the frictional engagement of the surface normally `at rest, it

sometimes happens that, unless positive means are provided for holding or maintaining the insert in a `fixed position relative to the stationary `leaf spring,` the pin on the liner may be sheared off or broken, due to movement of the' opposite faces or sides of which have contacting surfaces of "different frictional characteristics.

In other words, the surface of the liner on the.

same side as the retaining means and in contact with therelatively stationary leaf sprng,is preferably provided withya` coating of suitable organic material having a highcoefiicient of friction such as asphalt, synthetic resin,` beeswax or the like, adapted to positively resist relative movement between the liner and that leaf spring, while the opposite surface of the liner adjacent and in contact with the relatively movable spring leaf has a lower coefficient of friction or, in some cases, an anti-frictional surface to permit controlled movement of the latter leaf spring rela- `tive to the liner, without displacing the liner or shearing the fastening means thereon.

A further object consists in combining with the mechanical retaining means formed by the pin or projection of the liner, friction producing means on one side or face of the liner and` a friction reducing surface on the opposite side of the liner, so as to insure longitudinal displacement of the movable leaves of the spring relative tothe liners and the stationary leaves, without disturbing the retaining means or pins on gtheliners. i I Other objects and advantages of the invention will become `apparent from the following description when taken in conjunction with the accompanying claims and drawing.

: Referring to the drawing, `in which is shown preferred embodiments vof the invention:

Figure 1 is a fragmentary side elevation of a vehicle frame provided with a laminated leaf spring having my invention associated `there- Figure 2 is a detailed side elevation of th laminated spring shown in Figure l;

Figure V3 is a bottom plan View of the spring of Figure 2;

Figure `lv is an enlarged sectional detailed View taken substantially along the line 4-4 of Figure 2;

Figure `5 is a` detailed sectional view of the liner or insert;

Figure 6 is a detailed plan view of a full length liner or insert; and

s Figure 7.is a side view with parts in section,

`showing a full `length insert positioned between adjacent leaves of the spring.

` Referring to the drawing, in whichv like.- numerals'indicate like parts in the several views,` I0 designates a portion of the chassis frame of' a vehicle, and IIone of the rear wheels thereof. A laminated supporting spring I2 composed of a main spring leaf. I3, and a series of underlying spring leaves I4 of varying or graduated lengths, maybe connected by the shackle I6 to one end of the spring I2, as at I6', while the opposite end of the spring is pivotally connected to the frame as at I'I. The multiple spring I2 between its ends is securedto the rear axle I8 in any suitable tough fibrous material, such as low grade paper board stock. Each of the liners 2| has projecting outwardly or downwardly therefrom a pin or protuberance 22 suitably secured or embedded in the liner, as at 23 (Figure 5) and arranged to extend into a complementary opening or depression 24 formed in the adjacent end portion of the leaves I4. The pins 22 constitute mechanical means for securing the inserts 2| to the relatively stationary leaves and for preventing the movement of the inserts with the displaceable or movable leaves.

As particularly shown in Figure 4, the liner or insert 2I is positioned between the movable main spring leaf I3 and its adjacent relatively xed or4 stationary leaf spring I4 so as to maintain these leaves in proper spaced relation to each other. The liner also constitutes a bearing surface or member over which the leaf I3 is slidably and independently movable. As each insert 2l is connected through the pin 22 to one of the relatively stationary leaves, it will be seen that lunless the insert is maintained in a stationary -position relative to the spring leaf I3 when the latter is displaced, any longitudinal movement imparted to the liner relative to its adjacent fixed leaf IG would cause shearing or breaking off of the pin 22. By providing the opposite sides or faces of the inserts 2I with contacting surfaces having relatively different frictionalvcharacteristics, movement of the relatively movable leaf spring of each pair of adjacent springs, may be effected without danger of shearing or damaging the fastening means or pins 22. Accordingly, the face of each of the inserts 2| on the same side as the pin 22 and adjacent the relatively fixed leaf I4, is preferably provided with a stratum or coating of any suitable organic material 25, which has a high coemcient of friction, such as asphalt, synthetic resin or beeswax. The opposite side or face contiguous to the' movable leaf may be smooth so as to have a desired coefficient of friction, lower than the first mentioned side, or may be provided with a covering 26 of anti-frictional material, such as wax paper or the like, to permit a movement of the leaf I3 thereover, as explained in the above identified patents, without danger of causing movement of the liner 2I relative to its adjacent stationary leaf I4.

Thus, it will be seen that by providing one side of each of the liners 2I with a friction producing material and the opposite side with a friction reducing surface, the movable leaf or leaves may be displaced longitudinally relative t'o'both their associated liners and their adjacentstationary leaves, without disturbing the 'fixed position of the retaining means or pins 22 which connect the liners with the relatively stationary leaves. In other words, the mechanical fastening or retaining means provided by the pins 22 on Vthe inserts 2l have each coacting therewith, the frictional surface 25, which has a higher coefficient of friction than the opposite side 26 of the liner, in order to insure the liner being maintained with its adjacent stationary leaf in a relatively fixed position when its adjacent movable leaf is displaced during the travel of the vehicle.

Instead of providing partial or spaced inserts positioned adjacent the ends of the multiple leaf springs, a full length liner such as 2l (Figure 6) may be provided. The liner 2l is substantially coextensive in overall dimensions to the shorter of the adjacent pair of leaf springs with` which it is associated, and is interposed betwen a movable or main leaf spring Y28 and a relatively stationary or fixed leaf 29 by a suitablefastening means, such as the pins 3e which project outwardly therefrom so as to extend into openings 3| in the leaf 29 in substantially the same manner as the insert 2I previously described. The face of the insert 2I from which the pins 3D project, is preferably coated or has applied thereto a friction producing material 32, such as asphalt, tar or the like, while the opposite face 33 of the liner is preferably smooth or has a friction reducing material applied thereto, so as to offer only the desired amount of resistance to the longitudinal movement of the leaf 28, as explained in the aforesaid patents. Thus, simple and efficient means are provided for precluding the possibility of the pins 30 being sheared or damaged, due to displacement of the liner with the movable leaf spring 28.

A further advantage of the use of the pins 22 in combination with the frictional coating for preventing displacement of the inserts, is that the pins constitute a means for accurately positioning the inserts in exactly the correct relation to the spring leaves during original assembly of the springs, or during replacement or repair thereof. Hence there is no danger that the inserts will be initially incorrectly positioned and retained in such incorrect position by the frictional securing means.

It is to be understood that the several forms of the invention shown and described are merely illustrative of' preferred embodiments and that such changes may be made as fall within the purview of one skilled in the art without departing lfrom the spirit of the invention and the scope of the appended claims.

I claim:

1. A spring of the classv described including superimposed leaves, said leaves adjacent their ends having openings therein, a liner between each adjacent pair of leaves, said liner having retaining means projecting into one of the openings, one of each pair of adjacent leaves when the spring is displaced being movable relative to its adjacent leaf, each liner on the same side as the retaining means, having a coating of friction producing material and on its opposite side having a friction reducing surface so as to prevent shearing of the retaining means when the spring is displaced.

2. spring of the class described including superlmposed leaves, an insert between adjacent leaves having a projection extending into a complementary opening inthe adjacent leaf, -said insert on the same side as the projection having a coating of asphalt and on the opposite side a friction reducing surface to prevent shearing of the projection when the adjacent leaves are displaced longitudinallyrelative to each other.

3. A liner'adapted to be insertedbetween adjacent leaves of a laminated spring, said liner having a pin projecting outwardly from one side thereof, the surface of the liner on the same side as the pin having a coating of friction producing material andthe opposite surface of the liner being provided with a friction reducing surface.

4.' A liner adaptedto be inserted between adjacent leaves of a laminated spring, said liner having a pin extending'outwardly from one side thereof, the side of the liner adjacent the pin having a coating of asphalt and the opposite side having a friction reducing surface.

TOM H. THOMPSON. 

